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Remove devices with reserved ip addresses from Network

New Poster

Remove devices with reserved ip addresses from Network

I have 2 video servers that I had assigned static ip addresses from  the Comcast Arris TG1682G Modem.  I needed  to perform firmware upgrades to them both.  The upgrade results in the servers to restore itself to factory settings.

 

However I am unable to rejoin them into my home network due to duplicate MAC addresses.  So how do I remove the servers ( the ones that I had already assigned ip addresses) from my list of devices? They are currently appearing as being offline.  But I have no way of editing the configuration or simply deleting them from the Comcast gateway (10.0.0.1).

 

 

I have tried using Live Chat but the rep could not figure it out. Life would be so much simpler if you could 1. Delete any connected devices from your network and 2. see the list of devices that I have assigned ip addresses to.

Silver Problem Solver

Re: Remove devices with reserved ip addresses from Network

Have you tried a quick 2 sec press of the reset button on the back of the gateway?  Failing that, try a factory reset (press and hold the recessed reset button on the back of the device for over 15 secs, using a pen tip or whatever). You will lose any settings and will have to wait for the wireless captive portal to come up in a browser.

New Poster

Re: Remove devices with reserved ip addresses from Network

There has to be an easier way than doing a factory reset of the comcast modem. That would entail re-issuing ip addresses to all of my devices that I want to have a static ip.

Silver Problem Solver

Re: Remove devices with reserved ip addresses from Network

Not sure if this helps either, using DHCP if I go to delete an offline device in "connected devices", it shows up in Parental controls as a blocked device, but good luck!

New Poster

Re: Remove devices with reserved ip addresses from Network

yes it appears in blocked devices but it blocks the MAC address, not the ip address.  you can not have duplicate MAC addresses in a network.

New Poster

Re: Remove devices with reserved ip addresses from Network

You might try this.  I have a TC8305C modem and I use this method to delete "offline" devices so that I can re-use reserved IP addresses.  a) Block the device in the list of offline devices, then b) Remove the device from the list of blocked devices in Parental Controls.  Once both steps are taken the IP address and associated MAC address can be reassigned.

 

New Poster

Re: Remove devices with reserved ip addresses from Network

I have this same problem.  I am showing an unknown offline device with a static IP address showing previously connected with Ethernet cable.  I want to remove this device from holding my IP address 10.0.0.2.  The suggestion here of blocking and then removing the device under Parental controls does not work.  When I remove the device under Parental controls, it just goes back to the offline devices not blocked list.  I read a suggestion that this could be the MAC address of my wifi card? (I am not tech savvy so may be using the wrong terminology here).  I don't want this unknown device holding this static IP address.  How can I fix this or how can I put this device back online if I don't know what it is?  I tried searching my system for the MAC address but nothing came up.

 

P.S. I am getting an IP conflict on my laptop which is set to DHCP but the system keeps assigning it 10.0.0.7.  Nothing else is showing to have that IP address but I get the conflict error everyday now.  I have tried setting a static IP address for the laptop but it won't hold the setting change and reverts back DHCP with 10.0.0.7 and the conflict continues.  Any suggestions?

Frequent Visitor

Re: Remove devices with reserved ip addresses from Network

I have the same problem as well. I like to reserve IP addresses for everything on my network, so they don't end up with duplicate IP addresses if I restart the router. Truthfully, I don't know if the Xfinity router has that issue, but I've been assuming it does since that has been true of every other WiFi router that I've use in the past.

 

Anyway, I replaced a printer, and now I have the old printer still holding an IP address reservation with apparently no way to get rid of it. It's not a big deal at this point, but it's annoying and it's permanent clutter in the offline devices list.

 

I also tried removing the device and then removing from parental controls, and I also had the result that it just goes back to how it was before I tried deleting it from Offline Devices.

Frequent Visitor

This makes me SUPER angry.

This is UNACCEPTABLE. The ARRIS TG1682G  modem  will not let me edit names on the network, (would have been the easiest thing to program) ,  and now, like others here, I need to DELETE some devices from the list, (I do NOT need to BLOCK them I need to DELETE them) I discover it will not let me delete old devices from the network.
What kind of phony, low quality, stupid software feature is that!??? Who the heck designed those flaws into the system?

 

SUPER ANGRY.
MAKE THIS RIGHT, XFINITY. GET IT TOGETHER. 

New Poster

Re: Remove devices with reserved ip addresses from Network

I had a server with a reserved IP address.  My server died, and the admin page of the xfinity gateway/modem would not allow me to remove the reserved IP address.    I solved the limitiation of the admin page by spoofing the mac address on my new linux server.    This settings are not kept by you linux and get reset after a reboot.

    $ sudo ip link set dev eth0 down
    $ sudo ip link set dev eth0 address 00:15:a0:ee:c8:9c       (use the mac address you want to remove)
    $ sudo ip link set dev eth0 up
That reconnected to the modem and got the reserved IP that I wanted to remove.   That allows you to remove the reserved IP by making it use DHCP.

Not sure how to do it on Windows.   Here is another option if you don't have a linux server.   (I did not try this but I believe it would work just as good)  my next option was going to be using an old Netgear router and connecting it to the gateway.  Most routers allow you to change the mac address.    (xfinity modem---oldRouter---yourComputer)

 

The admin pages of the xfinity cable modem are  "poor"